I have one of these, I have not tried it in a boat but could be used that way. Its made for plugging into your mp3 player and then it transmitts to your car radio. but in practice it will plug into anything with a suitable jack, mp3 player, phone, cd player, tape player and computer head phones, then transmits to any radio in the area tuned to it. Cost is only ?6-8. (From E Bay . then stick a stripped down suitable sized radio into boat and control sound from shore.
Wireless FM Transmitter Car RadioIPOD NANO MP3 CD UK
Product Attributes:? Condition: New
Chipset Model: N/A
Retail Price: ?19.99 (including shipping fee)
Warranty: 3 years
Compatible with all audio device such as 128, 256, 512, ipod mp3 player and CD Player.
Powered by either 2 x AAA Batteries, It also include a Car Cigarette Lighter Power Cable, can get power from the car cigarette lighter socket. No need the batteries. Can get power from the car cigarette lighter socket
This product can quickly and easily set up the Digital Player and Car or Home audio system's wireless link
Frequency Channel: 106.7MHZ 107.1MHZ, 107.5 MHZ, 107.9MHZ
Modulation mode range 50HZ - 15KHZ wide band
Transmit distance > 30 feet
Synonym preference < - 60dB
High-clarity , full -stereo sound
Power light and frequency LED indicator
Size : (L) 88mm x (W) 42mm x (H) 20mm
Colour : white
Include a Car Cigarette Lighter Power Cable.
It can get power from the car cigarette lighter socket.
No need the batteries.
How to Use it?
Install the batteries (2xAAA) (not included) into the FM transmitter ,turn on the power.
Insert the audio input jack to The audio player's output socket.
Turn on the Audio Player, select the correct channel. The corresponding channel indicator light will on as you choose.
Turn on the FM Radio, tuning to corresponding channel then you could enjoy music.
Car Cigarette Lighter